1. Field Of The Invention
This invention is related to air conditioning systems and apparatuses, e.g. for heating or cooling air; in one aspect to such apparatuses with a coil in a plenum box; and in another aspect to an M-configured coil and drain pan for it; and in certain aspects to drain pans through which air flows to a coil.
2. Description of Related Art
By Jan. 1, 1992 U.S. federal regulations will require that certain air conditioning units have a seasonal energy efficiency ratio of at least 10.0. A variety of efforts have been made to develop systems which can satisfy this standard.
It is known in the art of air conditioning coil design that the efficiency of an air conditioning system can be increased by increasing the face area of a coil and by decreasing the number of tubing rows, thus decreasing the static pressure necessary to flow air through the coil. Prior art efforts at expanding the face area of a coil have resulted in a larger coil as far as overall length and width are concerned.
Coils are installed in housings, many of which are sized to meet common industry requirements. Also, in many buildings, the space allotted for installation of a housing with a coil therein is space in a closet or interior area which is limited by walls and ceilings. Consequently, enlarged coils (coils made larger to expand face area to increase system efficiency) either do not fit in the space typically made available for a coil; or the space itself must be increased to accommodate the larger coil. enlarging the space is often complicated, requiring the removal of existing walls or ceiling, re-routing of electrical and other conduits, and alteration of existing system housings and enclosures.
Limitations on the manner in which coils can be oriented limits the ways in which existing housings, enclosures, and spaces can be altered to accommodate an enlarged coil. Coil orientation is also limited by available drain pan design.
In various prior art air conditioning systems the blower of a furnace is used to propel air through a transition member connected to the furnace, through a coil, and into a plenum box. Through various openings in the plenum box air exits into conduits which carry it to various locations.
These prior art systems are relatively complex since they require a transition member and also the various connections between the transition member and the coil housing and between the coil housing and the plenum box. These systems are inefficient since the air moves from the coil in one direction, hits the interior of the plenum box, changes direction, and then exits, often after multiple encounters with the plenum's interior. The dimensions of the transition member and the dimensions of the connecting members often depend on the size of the coil that is used; so that even if several locations have an identical blower, different transition members, etc. may be required.
In accordance with 37 C.F.R. .sctn.1.56, the following are disclosed:
"Ruud Electric Furnaces," Ruud Air Conditioning Division, 1988.
"Cased Horizontal Furnace Coils Model 519E," Payne Air Conditioning, April, 1990.
"Ruud Indoor Coils," Ruud Air Conditioning Division, 1989.
"Cased Horizontal Furnace Coils," Payne Air Conditioning, 1990.
U.S. Pat. No. 2,022,523 discloses an air conditioning apparatus with a blower in an enclosure and a U-shaped duct with a discharge opening. Both heat exchange elements and cooling coils are disposed in the U-shaped duct.
U.S. Pat. No. 3,372,870 discloses an air treating assembly which includes a condensing unit, exhaust and air intake assembly, a filter, a blower assembly, a heater, a cooling coil and a mixing damper assembly.
U.S. Pat. No. 3,405,758 discloses an air mixing apparatus for controlling air flow in a duct, having blowers that blow air through a heating unit and through a cooling unit.
U.S. Pat. No. 3,411,569 discloses a combined heating-cooling unit.
U.S. Pat. No. 3,464,487 discloses an air handling unit with a housing enclosing blowers, a heating element, and a cooling element.
U.S. Pat. No. 3,540,526 discloses a rooftop air conditioning unit having a blower and evaporator-coil through which air is blown and then flows out from a housing outlet.
U.S. Pat. No. 3,625,022 discloses an air conditioning unit with a blower and coils. Conditioned air is exhausted into a chamber from which air-conveying conduits extend
U.S. Pat. No. 4,657,178 discloses an air mixing box for transferring conditioned air.
Certain prior art pan-coil combinations require two separate pans if the pan-coil is to be useful in a plurality of distinct orientations; e.g., one pan receives condensate when the pan-coil is used in a horizontal air flow mode, but then to use that same coil in an air upflow or downward flow mode, a second pan is needed.
There has long been a need for a coil of expanded face area for an air conditioning system which is useful in existing housings, enclosures, and available installation space. There has long been a need for such a coil which is not limited to a single orientation. There has long been a need for a drain pan for such a coil.
There has long been a need for an efficient air conditioning apparatus which utilizes the blower of a gas or electric furnace. There has long been a need for such an apparatus which is simple, easily made, easily installed, and easily accessed. There has long been a need for such an apparatus which efficiently moves cooled air (or heated air) from a plenum box. There has long been a need for such an apparatus that can efficiently accommodate different size, shape, and type coils.